Cervical Disc Displacement in Military Pilots.

INTRODUCTION: Cervical disc displacement (CDD) may disqualify pilots from flying and have a profound impact on military unit capability. The objective of this retrospective database review is to characterize the incidence and demographic predictors of symptomatic cervical spine disc displacement in pilots of fixed- and rotary-wing aircraft and ground-based controls. MATERIALS AND METHODS: The Defense Military Epidemiology Database was queried for first-occurrence ICD-9 code 722.0: CDD cases from 2007 to 2015. Injury count rates among aircraft groups and overall incidence per 1,000 person-years were calculated and standardized for age, gender, and military rank, and 95% confidence intervals (CIs) were compared to determine significance. RESULTS: There were 934 new cases of CDD among active duty U.S. Military pilots during the study period. The overall incidence of CDD in all pilots during this time frame was 2.715 per 1,000 person-years (95% CI, 2.603-2.830). Helicopter pilots had a significantly higher incidence compared to all other aircraft pilots and crew at 3.79 per 1,000 person-years (95% CI, 3.48-4.13). This finding remained statistically significant after standardizing for age, gender, and rank. Among all military officers, increasing age was a risk factor for CDD. CONCLUSIONS: The U.S. Military helicopter pilots have an increased risk compared to fixed-wing pilots and non-pilot controls. CDD remains a rare, though career-threatening, condition. Increased education and awareness training are warranted for both helicopter pilots and flight physicians to recognize signs and symptoms of cervical pathology. Continued investigations into preventive measures to minimize injury and time unfit for flight are warranted.

Risk of Appropriate Implantable Cardioverter-Defibrillator Therapies and Sudden Cardiac Death in Patients With Heart Failure With Improved Left Ventricular Ejection Fraction.

BACKGROUND: The benefit of implantable cardioverter-defibrillator (ICD) therapy is controversial in patients who have heart failure with improved left ventricular ejection fraction (EF) to >35% after implantation (HFimpEF). METHODS: Databases (Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar) were queried for studies in patients with ICD that reported the association between HFimpEF and arrhythmic events (AEs), defined as the combined incidence of ventricular arrhythmias, appropriate ICD intervention, and sudden cardiac death (primary composite end point). RESULTS: A total of 41 studies and 38,572 patients (11,135 with HFimpEF, 27,437 with persistent EF ≤35%) were included; mean follow-up was 43 months. HFimpEF was associated with decreased AEs (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.32 to 0.47; annual rate [AR] 4.1% vs 8%, p <0.01). Super-responders (EF ≥50%) had less risk of AEs than did patients with more modest reverse remodeling (EF >35% and <50%, OR 0.25, 95% CI 0.14 to 0.46, AR 2.7% vs 6.2%, p <0.01). Patients with HFimpEF who had an initial primary-prevention indication had less risk of AEs (OR 0.43, 95% CI 0.3 to 0.61, AR 5.1% vs 10.3%, p <0.01). Among patients with primary prevention who had never received appropriate ICD therapy at the time of generator change, HFimpEF was associated with decreased subsequent AEs (OR 0.26, 95% CI 0.12 to 0.59, AR 1.6% vs 4.8%, p <0.01). In conclusion, HFimpEF is associated with reduced, but not eliminated, risk for AEs in patients with ICDs. The decision to replace an ICD in subgroups at less risk should incorporate shared decision making based on risks for subsequent AEs and procedural complications.

Prognostic value of late-gadolinium enhancement on cardiac magnetic resonance in patients with cardiac sarcoidosis.

BACKGROUND: Late-gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is a predictor of adverse events in patients with cardiac sarcoidosis (CS), but available studies had small sample sizes and did not consider all relevant endpoints. OBJECTIVE: To evaluate the association between LGE on CMR in patients with CS and mortality, ventricular arrhythmias (VA) and sudden cardiac death (SCD), and heart failure (HF) hospitalization. METHODS: A literature search was conducted for studies reporting the association between LGE in CS and the study endpoints. The endpoints were mortality, VA and SCD, and HF hospitalization. The search included the following databases: Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimum follow-up duration was 1 year. RESULTS: A total of 17 studies and 1915 CS patients (595 with LGE vs. 1320 without LGE) were included; mean follow-up was 3.3 years (ranging between 17 and 84 months). LGE was associated with increased all-cause mortality (OR 6.05, 95% CI 3.16-11.58; p < .01), cardiovascular mortality (OR 5.83, 95% CI 2.89-11.77; p < .01), and VA and SCD (OR 16.48, 95% CI 8.29-32.73; p < .01). Biventricular LGE was associated with increased VA and SCD (OR 6.11, 95% CI 1.14-32.68; p = .035). LGE was associated with an increased HF hospitalization (OR 17.47, 95% CI 5.54-55.03; p < .01). Heterogeneity was low: df = 7 (p = .43), I2 = 0%. CONCLUSIONS: LGE in CS patients is associated with increased mortality, VA and SCD, and HF hospitalization. Biventricular LGE is associated with an increased risk of VA and SCD.

Synchronous Multifocal Necrotizing Fasciitis: A Case Report.

CASE: An immunocompetent 43-year-old man was diagnosed with necrotizing fasciitis of his forearm. Despite receiving appropriate treatment, his clinical condition continued to deteriorate. Further evaluation revealed subsequent proliferation of the infection to multiple noncontiguous areas of the body consistent with a rare condition known as synchronous multifocal necrotizing fasciitis. Prompt identification, followed by serial debridements of all affected areas, ultimately saved the patient's life. CONCLUSION: This unusual multifocal presentation of necrotizing fasciitis can produce diagnostic uncertainty and delay life-saving treatment. Early recognition, followed by prompt treatment, is paramount for reducing morbidity and mortality associated with this devastating infection.

Elevated Environmental Carbon Dioxide Exposure Confounding Physiologic Events in Aviators?

INTRODUCTION: Physiological events (PEs) are a growing problem for US military aviation with detrimental risks to safety and mission readiness. Seeking causative factors is, therefore, of high importance. There is no evidence to date associating carbon dioxide (CO2) pre-flight exposure and decompression sickness (DCS) in aviators. MATERIALS AND METHODS: This study is a case series of six aviators with PE after being exposed to a rapid decompression event (RDE) with symptoms consistent with type II DCS. The analysis includes retrospective review of flight and environmental data to further assess a possible link between CO2 levels and altitude physiologic events (PEs). IRB approval was obtained for this study. RESULTS: This case series presents six aviators with PE after being exposed to a rapid decompression event (RDE) with symptoms consistent with type II DCS. Another three aviators were also exposed to a RDE, but remained asymptomatic. All events involved tactical jet aircraft flying at an average of 35,600' Mean Sea Level (MSL) when a RDE occurred, Retrospective reviews led to the discovery that the affected individuals were exposed, pre-flight, to poor indoor air quality demonstrated by elevated levels of measured CO2. CONCLUSION: PEs are a growing safety concern for the aviation community in the military. As such, increasing measures are taken to ensure safety of flight and completion of the mission. To date, there is no correlation of CO2 exposure and altitude DCS. While elevated CO2 levels cannot be conclusively implicated as causative, this case series suggests a potential role of CO2 in altitude DCS through CO2 direct involvement with emboli gas composition, as well as pro-inflammatory cascade. Aviators exposed to elevated CO2 in poorly ventilated rooms developed PE symptoms consistent with DCS, while at the same command, aviators that were exposed to a well ventilated room did not. This report is far from an answer, but does demonstrate an interesting case series that draws some questions about CO2's role in these aviator's DCS experience. Other explanations are plausible, including the accurate diagnosis of DCS, health variables amongst the aviators, and differences in aircraft and On-Board Oxygen Generation Systems (OBOGS). For a better understanding, the role of environmental CO2 and pre-flight exposure as a risk of DCS should be reviewed.